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ContextSet

ContextSet is the type of ctx.set. It describes response changes that the framework applies at the end of the request lifecycle, after mapResponse.

interface ContextSet {
  status?: number;
  headers?: Record<string, string | string[]> | Headers;
}

Fields​

status​

  • Type: number | undefined
  • Description: The HTTP status to set on the response. When omitted, the handler's status is preserved. A response with an error status (400 or higher) keeps that status: ctx.set.status only restyles success responses.

headers​

  • Type: Record<string, string | string[]> | Headers | undefined
  • Description: Headers to merge over the response's existing headers. Explicitly set values win. An array value appends every entry instead of replacing. A scalar set-cookie is appended too, so cookies from the handler and from ctx.set both survive.

ctx.set.headers is always defined: it is created on first access, so this never throws:

ctx.set.headers["x-request-id"] = ctx.headers.get("x-request-id") ?? "none";

Example​

export async function POST(ctx: BurgerContext) {
  ctx.set = {
    status: 201,
    headers: { "x-version": "1.0.0" },
  };
  return Response.json({ created: true });
}

The mutation is applied by applySet at the pipeline exit, after mapResponse hooks run. See Response Mutation.